[PATCH RFT] ARM64: cpu: support 64-bit stack top in ENTRY_FUNCTION_WITHSTACK

[Ahmad Fatoum]

ENTRY_FUNCTION_WITHSTACK was written with the naive assumption that
there will always be some memory in the first 32-bit of the address
space to be used as early stack. There are SoCs out there though with
sole on-chip SRAM > 4G. Accommodate this by accepting full 64-bit stack
pointers in ENTRY_FUNCTION_WITHSTACK.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/arm/cpu/head_64.S             | 2 +-
 arch/arm/include/asm/barebox-arm.h | 2 +-
 arch/arm/lib/pbl.lds.S             | 7 ++++---
 include/asm-generic/pointer.h      | 2 ++
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/head_64.S b/arch/arm/cpu/head_64.S
index 398c4d3471e0..546efc263a06 100644
--- a/arch/arm/cpu/head_64.S
+++ b/arch/arm/cpu/head_64.S
@@ -11,7 +11,7 @@
 ENTRY(__barebox_arm64_head)
 	nop
 	adr x9, __pbl_board_stack_top
-	ldr w9, [x9]
+	ldr x9, [x9]
 	cbz x9, 1f
 	mov sp, x9
 1:
diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index eb31ca278821..aceb7fdf74f8 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -158,7 +158,7 @@ void __barebox_arm64_head(ulong x0, ulong x1, ulong x2);
 				(ulong r0, ulong r1, ulong r2)		\
 		{							\
 			static __section(.pbl_board_stack_top_##name)	\
-				const u32 __stack_top = (stack_top);	\
+				const ulong __stack_top = (stack_top);	\
 			__keep_symbolref(__barebox_arm64_head);		\
 			__keep_symbolref(__stack_top);			\
 			__##name(r0, r1, r2);				\
diff --git a/arch/arm/lib/pbl.lds.S b/arch/arm/lib/pbl.lds.S
index 114ec7bc8195..2b4b1d6a9513 100644
--- a/arch/arm/lib/pbl.lds.S
+++ b/arch/arm/lib/pbl.lds.S
@@ -4,6 +4,7 @@
 #include <linux/sizes.h>
 #include <asm/barebox.lds.h>
 #include <asm-generic/memory_layout.h>
+#include <asm-generic/pointer.h>
 
 #ifdef CONFIG_PBL_RELOCATABLE
 #define BASE	0x0
@@ -44,14 +45,14 @@ SECTIONS
 	. = ALIGN(4);
 	.rodata : { *(.rodata*) }
 
-	. = ALIGN(4);
+	. = ALIGN(ASM_SZPTR);
 	__pbl_board_stack_top = .;
 	.rodata.pbl_board_stack_top : {
 		*(.pbl_board_stack_top_*)
 		/* Dummy for when BootROM sets up usable stack */
-		LONG(0x00000000);
+		ASM_LD_PTR(0x00000000)
 	}
-	ASSERT(. - __pbl_board_stack_top <= 8, "Only One PBL per Image allowed")
+	ASSERT(. - __pbl_board_stack_top <= 2 * ASM_SZPTR, "Only One PBL per Image allowed")
 
 	.barebox_imd : { BAREBOX_IMD }
 
diff --git a/include/asm-generic/pointer.h b/include/asm-generic/pointer.h
index 8b9600b02939..89817ce59ebc 100644
--- a/include/asm-generic/pointer.h
+++ b/include/asm-generic/pointer.h
@@ -8,6 +8,7 @@
 #define ASM_PTR		.quad
 #define ASM_SZPTR	8
 #define ASM_LGPTR	3
+#define ASM_LD_PTR(x)	QUAD(x)
 #else
 #define ASM_PTR		".quad"
 #define ASM_SZPTR	"8"
@@ -18,6 +19,7 @@
 #define ASM_PTR		.word
 #define ASM_SZPTR	4
 #define ASM_LGPTR	2
+#define ASM_LD_PTR(x)	LONG(x)
 #else
 #define ASM_PTR		".word"
 #define ASM_SZPTR	"4"
-- 
2.39.2